resuscitation

June 2, 2014

Bedside Ultrasound Clip Quiz: Abdominal pain and fever! #FOAMed, #FOAMcc, #FOAMus

Saw this poor fellow recently who presented to the ED with fever and abdominal pain. 73 years young. He came to my attention because of borderline BP (95 systolic) and a lactate of 4.5 mmol.

Here is a transverse scan at his lower right costal margin:

 

What do you think?

Turns out he had been having pain for about two weeks, and it had intensified about two days ago. His wife dragged him in.

What would you do?

 

 

 

 

 

 

 

 

 

 

 

This is septated fluid collection around the liver.  With the fever and history, sounds pretty suspicious for a septic source. After carefully scanning in all angles and watching for a while to make sure this wasn’t a strangely placed loop of bowel, a 22g needle aspiration showed cloudy bilious fluid and a trip to the OR a couple of hours later revealed a perforated duodenal ulcer.

He made it ok.

 

cheers

 

Philippe

April 13, 2014

An Update on Pulmonary Embolism: NEJM’s PIETHO Study…what’s the verdict? #FOAMed, #FOAMcc

As has been discussed in a previous post (http://wp.me/p1avUV-7T), patients with sub-massive PE (hypoxic, tachycardic, some troponin rise, etc…but no hypotension) remain in a grey zone, which is, to me , a dubious situation at best – their mortality can be up to 15%, morbidity likely more.  Everyone agrees the low-risk patients don’t need thrombolysis, and everyone pretty much agrees that the patient in shock needs it.  There is data out there suggesting that some patients clearly benefit from thrombolysis despite not being in shock, in good part relating to avoiding chronic pulmonary hypertension and its consequences.

The issue for many clinicians is that they have a “stable” patient in front of them, and they are considering giving them a drug that can potentially give them a bleed in the head and leave them dead or crippled. Many shy away from this. Part of this is cultural, because the same docs probably wouldn’t hesitate giving the drug to a lateral or posterior MI, which is not likely to kill you, or even leave you a cardiac cripple (just to be clear, I’m not advocating against thrombolysis in these cases, just trying to find a parallel), but since the AHA guidelines say to do it and everyone else does it, there’s no trepidation. It is the standard of care.  For most of us acute care clinicians who do not do outpatient medicine, if the patient survives and gets discharged home, chalk one up in the win column. But, as has become clear in recent years with the post-critical illness syndromes, morbidity can be just as important as mortality, especially in the younger patients. Kline et al (Chest, 2009) showed how almost 50% of “submassive PE” patients treated with anticoagulation alone had dyspnea or exercise intolerance at 6 months. They only had a 15% improvement in their pulmonary artery pressures (mean 45 mmhg).

What are the real risks? Pooling the data together gives a value around 2% with a spread between 0.8% and 8%, more or less. This represents each patient’s inherent risk of bleeding, as well as some of the inconsistencies with post-thrombolysis anticoagulation (safest to aim for 1.5-2 x PTT baseline in the first 48h).

The MOPETT trial which, as a #FOAMite you have certainly come across, showed that a half-dose of TPA was highly effective, and they felt it might be possible to go lower. The physiological beauty in that is that, unlike other sites we thrombolyse with full dose TPA, the lungs get 100% of the TPA (coronary artery gets maybe 5%, brain gets 15%).  Mind you, of course, the culprit clot/artery obviously doesn’t get 100%, but much, much more (if we figure that you need about 50% vascular area occlusion to cause RV dysfunction) TPA per “clot” than other pathologies. One can argue that anatomically, there is a greater clot burden than coronary or arterial thrombolysis, which may offset this somewhat. However, the date was quite clear in this trial that the therapy was effective, and the bleeding was none.

Ok, so let’s get to the PIETHO. 1000 patients, TPA+heparin vs heparin alone in normotensive but intermediate risk patients. So, first question is how was that risk defined?  Patients needed to have echocardiographic/CT signs of RV dysfunction AND a positive troponin. Interestingly enough, onset of symptoms was up to 15 days before randomization…not exactly early treatment, and unfortunately there is no information about the actual time to thrombolysis or subgrouping.  The results were as one could imagine. The combined endpoint of death or hemodynamic decompensation was 2.6% in the thrombolytic group vs 5.6% in the anticoagulation.  I’m not a fan of combined endpoints. Hemorrhagic stroke was 2.0% vs 0.2%. Their conclusion? Exercise caution. Hmmm…not much of a step forward. Basically tells us what we know. It helps the hemodynamics, but you can bleed. They do re-affirm that bleeding is more likely in the over-75.

 

What do we REALLY need to figure out? 

1. echographic risk stratification – at least into moderate and severe RV dysfunction.

2. longer term outcomes (hopefully PIETHO has a follow-up study in the pipeline, since they had good numbers).

3. a point-of-care study – time is of the essence, and may have an impact on dosage. IMHO thrombolysis should be done within a few hours of presentation at most.

4. further dosage data – 1/2? 1/3? 1/4? small boluses q1h until RV function improves?

I wish I could do it, but community hospitals don’t have the ideal setup, nor do I have a research team that can handle something of this scale. But surely someone can!

 

Bottom line?

It won’t change my practice. I will continue to offer thrombolysis in select cases, especially the younger patients, who obviously have a lower risk of bleeding, and stand to benefit the most, as pulmonary hypertension  can be crippling. I know I’d take the risk of bleeding when I see 50% dyspnea/exercise intolerance two years down the road…

Finally, bedside ultrasound to anyone with dyspnea/hypoxia should be a standard of care for every acute care physician. No ifs, ands or buts, no exception. Waiting for a CT angio or formal (read daytime hours) echocardiogram is, to me, unacceptable. If you, a friend or family member were in that ER bed, would you trust a physical examination and a CXR to rule out the need for an immediate intervention? I wouldn’t, not my own, and not even Dr. Bates’, Dr. DeGowin’s or Dr. Sapira’s, or all three combined.

cheers!

 

 

 

Kline JA, Steuerwald MT, Marchick MR, Hernandez-Nino J, Rose GA. Prospective evaluation of right ventricular function and functional status 6 months after acute submassive pulmonary embolism: frequency of persistent or subsequent elevation in estimated pulmonary artery pressure. Chest 2009;136:1202e1210.

Guy Meyer, M.D., Eric Vicaut, M.D., Thierry Danays, M.D., Giancarlo Agnelli, M.D., Cecilia Becattini, M.D., Jan Beyer-Westendorf, M.D., Erich Bluhmki, M.D., Ph.D., Helene Bouvaist, M.D., Benjamin Brenner, M.D., Francis Couturaud, M.D., Ph.D., Claudia Dellas, M.D., Klaus Empen, M.D., Ana Franca, M.D., Nazzareno Galiè, M.D., Annette Geibel, M.D., Samuel Z. Goldhaber, M.D., David Jimenez, M.D., Ph.D., Matija Kozak, M.D., Christian Kupatt, M.D., Nils Kucher, M.D., Irene M. Lang, M.D., Mareike Lankeit, M.D., Nicolas Meneveau, M.D., Ph.D., Gerard Pacouret, M.D., Massimiliano Palazzini, M.D., Antoniu Petris, M.D., Ph.D., Piotr Pruszczyk, M.D., Matteo Rugolotto, M.D., Aldo Salvi, M.D., Sebastian Schellong, M.D., Mustapha Sebbane, M.D., Bozena Sobkowicz, M.D., Branislav S. Stefanovic, M.D., Ph.D., Holger Thiele, M.D., Adam Torbicki, M.D., Franck Verschuren, M.D., Ph.D., and Stavros V. Konstantinides, M.D., for the PEITHO Investigators*, Fibrinolysis for Patients with Intermediate- Risk Pulmonary Embolism, N Engl J Med 2014;370:1402-11.

Mohsen Sharifi, MDa,b,*, Curt Bay, PhDb, Laura Skrocki, DOa, Farnoosh Rahimi, MDa, and Mahshid Mehdipour, DMDa,b, “MOPETT” Investigators, Moderate Pulmonary Embolism Treated With Thrombolysis (from the “MOPETT” Trial), Am J Cardiol 2012

March 7, 2014

Bedside Ultrasound and PEA: CPR or no CPR…? #FOAMed, #FOAMcc

The usefulness of bedside ultrasound in cardiac arrest is clear, giving the clinician instant information on the hemodynamic process resulting in arrest. My arrest sequence is generally done as follows:

Step 1: IVC assessment

Step 2: Subxiphoid cardiac views

Step 3: Lung views if pneumothorax suspected.

Step 4: remaining views if possible (eg abdominal views to find source of bleeding, etc…)

The important part (as per current recommendations) is to have minimal interference on chest compressions. The IVC view, albeit jumpy, can generally be obtained during CPR.  The subxiphoid view should be “prepared” during CPR, meaning that the sonographer warns the team member doing CPR not to stop compressions until he is told to do so (unless the team are already used to ultrasound in cardiac arrest), the probe positioned optimally, then instruction given to stop for five seconds while a look +/- loop is acquired. This should be enough to look for pericardial effusion, RV/LV ratio and LV contractility. In fact, experienced sonographers can usually get this while CPR is going on in many cases. Then CPR should be restarted. Hence for now, minimal interruptions in CPR (until the concept of “stutter CPR” really emerges!!!).

Here are a couple of views with active CPR:

In this case there is  a clear RV overload with a dynamic but underfilled LV.

From the information obtained in those 5 seconds, one should be able to consider the need for volume (hypovolemia), thrombolytics  (pulmonary embolism suspected) or drainage of fluid (tamponade) or air (pneumothorax). The possibility of an acute myocardial infarction must be considered as it is one of the most common causes but is difficult to confirm by ultrasound.

Pulseless Electrical Activity

This may be the most exciting area in which ultrasound will change management.  In the absence of ultrasound, all PEA is more or less alike: there is organized electrical activity, but no pulse. Physiologically however, the range of diagnoses is very wide, with on one end, a perfectly good heart that is empty (hypovolemic shock in extremis), and on the other, cardiac standstill despite electrical activity. An astute physician does not need a randomized clinical trial to know that the management and prognoses of those two extremes are very different. Without bedside ultrasound, however, these would appear identical: “PEA.”

 The heart rate cannot be relied on since it will largely depend on the phase (both would begin as tachycardic, then eventually bradycardic until asystole occurs).

Notwithstanding guidelines,  the information obtained should be considered strongly. If we start by looking at the first end of the spectrum, there would be no physiological rationale for performing chest compressions or an empty and hyperdynamic ventricle: rapid infusers and vasopressors (to recruit venous unstressed volume) should be used instead. At the other end, the heart in standstill definitely needs compressions. Of course, there is then the whole range of varying RV and LV pathologies, tamponade, etc, all of which need to be dealt with individually. It is really a huge grey zone…

CPR or no CPR?

A very important question is whether CPR should or should not be performed in certain cases of PEA.  Certainly ACLS protocol dictates so. However, ACLS has not yet truly integrated bedside ultrasound into management, only suggests in a very loose way – understandably since the protocols must be applied by all, and still only few use it regularly.

I have to credit Dr. Sue, an ER doc from Atlanta, who asked me the question about CPR in extreme hypotension, and I had to rewind in my mind the cases in which I had used physiological information to overrule the ACLS protocol in one direction or another and try to formulate an answer.

It is an excellent question and made me realize that there is no clear answer for two reasons:

One: PEA is not a diagnosis but a clinical syndrome. It relies on manual pulse check (unless the arrest occurs in a patient with an arterial line), hence the line between severe hypotension and true PEA is difficult to determine. Technically and physiologically speaking, if the LV contraction is sufficient to open the aortic valve, there is a “pulse.” Now how far along the arterial circuit this pulse travels is not known…unless it is monitored.

Two: The key question then becomes the following: at what level of endogenous blood pressure is the perfusion better than with “good” CPR?  We do not yet have that answer. The coronary perfusion pressure (diastolic pressure – wedge pressure) data often quotes a minimal range of 15-25 mmhg, which – if we arbitrarily choose a high-ish wedge – would suggest we need a diastolic pressure in the 40’s (also note that that data is imperfect). Hence the arterial line. Perhaps there could be a role for tissue saturation/near-infrared spectroscopy or other microvascular flow indices in the future…

Now what about the huge spectrum of cases in between?  Let us exclude the cases with immediately reversible causes such as tamponade and pneumothorax, where the initial management is clear, and instead focus on differing levels of RV and LV dysfunction resulting in the absence of a palpable pulse.

Predominant RV failure – although PE should be strongly suspected and thrombolysis considered, the question remains about management if you see a hyperdynamic but underfilled LV.  CPR would appear reasonable in an effort to try to get some RV to LA flow. Endotracheal milrinone, sometimes used in cardiac anasthesia, can be an option as it provides inotropy and pulmonary vasodilation.

Predominant LV or biventricular failure – if cardiac activity is present, it seems imperative to start an infusion of vasopressors, and traditionally, do CPR until there is a measurable blood pressure. I have used CPR with progressing bradycardic rhythms for a few seconds to circulate the epinephrine, with at least short-term success.

Here is a typical LV “PEA” from the subxiphoid view:

Ideally, an arterial line would be very useful in these patients, and may help to decide on an individual basis when CPR should be used. Remember that CPR on a beating heart will likely worsen cardiac output as asynchronicity and increased mean intrathoracic pressure will impair filling.

Additionally, the arterial line also allows us to notice small trends during resuscitation, such as seeing that a few seconds of CPR may help circulate a bolus of vasopressor and enable it to take effect – progressive BP increase, or that the BP may be trending downwards despite vasopressor infusion – CPR may be useful until enough vasopressor/inotropes have infused.

Bottom Line:

1. if possible, put in an arterial line

2. bedside ultrasound is mandatory if you don’t want to miss anything reversible

3. if you don’t have a palpable pulse and your diastolic pressure (arterial line) is less than 40, consider some CPR until vasopressors/inotropes have had effect.

4. if you are lucky enough to have ECMO (shout out to Joe and Zack at http://www.edecmo.org)  or other mechanical support, it would be the time to consider!

I think this is actually a really interesting area to develop, and I’d really, really like to hear what other sonographer-resuscitationists are doing, or what anyone else might think!

 

Philippe

 

Joe Bellezzo – yes, THE Joe, says:

Phil, I agree with all your points here. Great post! As you know, Shinar, Weingart and I recently published a rant on PEA (over at http://www.edecmo.org/13) and Weingart threw out two possible new monikers: PRE-M (Pulseless Rythm with Echocardiographic – Motion) and PRE-S (Pulseless Rythm with Echocardiographic – Standstill). I don’t disagree with any of those concepts but I think its simpler than that.

PRE-S (standstill) = asystole and you start compressions.
PRE-M (organized cardiac activity) = profound shock. In this setting I like the recent Littmann paper that gives a simplified approach (http://edecmo.org/wp-content/uploads/2014/08/A-Simplified-and-Structured-Teaching-Tool-for-the-Evaluation-and-Management-of-Pulseless-Electrical-Activity.pdf).

As you pointed out above, the real big question is at what point do you start compressions when you have cardiac motion? Your points above are spot on. The problem with compressions on a beating heart is that you don’t know what your end-point is. You lose the ability to do minute-minute diagnostics and doing any procedures with ongoing compressions is tough. And it seems to be a knee-jerk reaction for the RN or pharmacist to have an amp of epi ready to blast away at this point. NO!

I wait. I do stuff first. Step 1 is ECHO. If PRE-M (aka profound shock): EKG and arterial line NOW. Step 2: Stop, think and decide what you think is your top probable etiology of this profound shock and fix that. Step 3: reassess = repeat echo, EKG, and see what your art line pressures are doing. I try to do all that before I start compressions.

Example: “PEA” hits your door. Echo shows a wall motion abnormality and hypokinesis. EKG suggests ischemia but is not obvious STEMI. art line goes in simultaneously. I think this is MI. This heart does NOT NEED epi 1 mg! This is cardiogenic shock and I need to fix some stuff before I start pushing on the chest and blasting superhuman doses of epi! I usually start with a push dose epi (10-20 mics or so) while a pressor drip is prepped. Calcium bolus is given. I likely start dobutamine here (or milrenone if beta blocked). If that fixes your problem, then the pt goes to the cath lab. If it doesn’t, I cannulate and put the pt on VA-ECMO.

And what if I were wrong? what if this were a big PE? massive beta blocker OD? the protocol above is works in those cases too.

An aside, since you already placed a femoral venous line….and you popped in the Art line immediately, you have nice conduits to upsize to ECMO cannulas.

Great post Phil!

 

Thanks for sharing your approach!  As you know and clearly show, a sensical physiological approach is absolutely needed in a day and age when we can (bedside ultrasound) see what’s really going on, and we can (ECMO) give these patients a fighting chance!  See you at BMBTL in a couple of weeks!

Philippe

 

PS Joe (and Zack and Scott) will be talking about all this and more at CCUS 2015! http://www.ccusinstitute.org to register soon!

February 23, 2014

“Doc, I can breathe!” – Thrombolysis in PE…a case discussion. #FOAMed, #FOAMcc

So I was on call last weekend and got a call from one of the internists on the ward about a potential admission who may need dialysis.   She was a woman in her 60’s, diabetic, hypertensive with minimal baseline renal dysfunction, who had been admitted with a hepatic abscess due to biliary obstruction. This had been stented and a pigtail catheter had been inserted to drain the abscess.  However, over the last few days, her creatinine had risen to about 500 and she was becoming oliguric.  Her O2 requirements had also increased and she was now on 15 liters by nasal prongs. This had been ascribed to pleural effusion and possible pneumonia.

When I saw this lady, she was visibly dyspneic at 30 with a heart rate 115-120 and a systolic BP of about 105-110, saturating 90% on 50% face mask.

So on physical examination, she had a soft abdomen (the first thing I feel just before I put probe to skin), her skin was cool, and the CUSE revealed a large (>20mm) IVC with no respiratory variation (despite the effort).  I unfortunately forgot to hit the record clip button…and the parasternal long axis and apical 4 chamber are here:

Lung views showed “A” profiles except for the right base which had a small effusion and some consolidation/atelectasis and some B lines, but not very extensive.

So further assessment revealed she was not a smoker, previously quite active and easily able to go up and down several flights of stairs.  She had noted dyspnea about 3 days ago, without chest pain. There were no leg symptoms, and she had been on LMWH for dot prophylaxis.  The CXR was not very impressive – in a sense that there was not enough parenchymal disease to explain pulmonary hypertension.

This is PE until proven otherwise, and I would have been comfortable without further confirmation, but with the presence of some lung disease and an intrahepatic catheter, I preferred to have 100% confirmation before initiating thrombolysis.

After CT angiogram confirming bilateral and extensive embolism, I had a thorough discussion with her and her family and they all agreed to go ahead with TPA.  She was quite concerned with cardiorespiratory limitation, given that she was quite active. She was comfortable with a quoted risk of intracerebral bleeding below 2%. I used the MOPETT half-dose of 50mg.

Overnight, her HR slowed to about 100, and sats increased to 93-94%.

When I rounded on her in the morning, she said “Doc, I can breathe!” with a big grin. Her HR was 95-100, she was not on 3 litters by NPs, BP 115-120 systolic, and CUSE showed:

So we can see that even though the RV is still quite impaired, it has decreased in size and the LV is now filling better. This was about 12-13h post thrombolysis. She was able to sit up without dyspnea and mobilize to the chair. Her IVC, although it remained around 18-19 mm, had clear respiratory variation.

So…success? Who really knows. It is concievable that, with heparin alone, she might have improved similarly. It is possible. I’m not putting this up to formally support the concept of thrombolysis in “submassive” PE but more to contribute to the #FOAMed discussion regarding the “grey zone” of thrombolysis, since she was technically not in shock (eg SBP>90, lactate normal), but the degree of impairment of the RV to me and the clinical picture, 3 days post, was concerning enough to warrant thrombolysis, but importantly to stress the following:

Point 1: the importance of bedside ultrasound, especially in acute cases.  Without it, over a weekend, and with a patient in renal failure, how quickly would I have ordered a CT angio?  Not without some hesitation…

I won’t review the MOPETT trial, these guys did a much better job than I could hope to, so definitely listen to this if this topic is of any interest to you (and it should!!!):

http://emcrit.org/wee/mopett-trial/

http://ragepodcast.com/rage-session-two/

Great case debates in the RAGE podcast.

Keep in mind that morbidity, not mortality, is the main thing to focus on in sub-massive embolism and the MOPETT – even though I don’t really like the term, its quite vague – benefit in embolism with shock is quite clear.

Point 2: Equally interesting to me was the fact that the renal failure improved. In fact, overnight following thrombolysis, she had a urine output (without diuretic) over a litre, and over the next few days her creatinine normalized and renal replacement therapy was not needed.  Interesting, since she even got a good blast of toxic dye with the CT.  Some will feel that it is the improvement in CO that improved renal function, and this may be partly true, but in view of the lack of “systemic shock,” I think that venous decompression resolved the congestive renal failure, which I think was the main cause of her ARF. I posted about this topic a few months ago, so for more on this see:

http://thinkingcriticalcare.com/2013/09/25/chf-associated-renal-failure-low-flow-or-not/

so thanks for reading and love to hear anyone’s opinion!

PR

COMMENTS:

QUESTION. IF SOMEONE DOES NOT HAVE A PALPABLE PULSE BUT HAS CARDIAC ACTIVITY ON THE ECHO AND RATE IS 90 AND BP IS 50.  DO YOU CONSIDER THIS PEA AND INITIATE CPR?

SEAN

Great question!  There is a whole grey area in “PEA” and management is unclear. I don’t think there is a single answer to that, but physiologically and without further information about RV/LV, I would say your patient needs vasopressor/inotrope support, so I would probably give a small bolus of epi (maybe 100ug) and start an infusion. If I see little reaction (eg HR/BP doesn’t pick up in 30 seconds, I would probably give a short cycle of CPR to get the epi back to the heart.   Of course, hopefully there is a reversible cause (MI/PE), that can be addressed.

Thanks!

 

Philippe

January 29, 2014

CCUS 2014: Taking your Ultrasound Game to another level! Montreal may 9-11, 2014!

Registration is open!

For the 7th edition of our Annual Symposium, we’ve assembled a great cast of characters to bring your bedside ultrasound game to a whole new level! Whether you’re a novice or have some experience in bedside ultrasound, we’re sure you’ll find our program very interesting, as the perspective we have chosen to take is patient-based, with each lecture explaining how ultrasound findings are integrated into clinical decision-making.

First of all, it’s in Montreal, May 10th and 11th, 2014. If you’re from out of town, its an awesome city to visit, and if you’re a Montrealer, well, it’s an awesome conference at home!

Indeed, this isn’t “just” a “how-to” course – although that is what we’ll be covering in the workshops which will follow each lecture – but a “how to integrate ultrasound into your daily practice” course, so no matter what your level is, you’ll find something suited for you. The workshops will be divided into novice and experienced and with a low participant to faculty ratio, will ensure a great experience.

So what are we going to be talking about?

In the CC/ED/hospital scene:

–       the patient with chest pain, by Max Meineiri

–       the patient with CHF, by Mike Stone

–       the patient with renal failure, by Sara Sebbag

–       the patient with a swollenleg, by Michael Woo

–       what’s my patient’s volume status? By Ashraf Fayad

–       the patient with a decreased level of consciousness, by Robert Chen

–       the patient in shock, by JF Lanctot and Max Valois

–       the patient with abdominal pain, by Haney Mallemat

–       the patient with a bowel obstruction

–       the patient with broken bones: finding and freezing, by Catherine Nix

–       the patient with dyspnea, by Alberto Goffi and Edgar Hockmann (KEYNOTE)

–       the hemodynamically unstable patient: multi-modality assessment, by Andre Denault (KEYNOTE)

In the office scene:

–       the patient with a neck mass, by Sarah Sebbag

–       the patient with arthritis, by Alessandra Bruns

Here is the program:

CCUS 2014 Master Programme

Who made this up?  Our scientific committee is made up of Michael Woo, Catherine Nix, Edgar Hockmann, Alberto Goffi and Andre Denault, who is also the co-chair – with myself – of this year’s symposium.

For those of you part of the twitterverse and #FOAMed movement, you’ll get a chance to meet @criticalcarenow (Haney), @bedsidesono (Mike), @nobleultrasound (Vicki), @EGLS_JFandMax (JF and Max) and @ThinkingCC (yours truly)…and Matt (pulmccm.org) will be there to chronicle the event and bring the highlights to the #FOAMed world.

So who should come?  Anyone taking care of sick patients.  If you’re an ED doc, ICU doc, hospitalist, anaesthetist, surgeon, student or resident, this stuff is gold. Even if most of your practice is office-based, precise assessment of dyspnea, volume status and cardiac function is highly practical.

Additionally, there are several very interesting pre-congress courses taking place on May 9th, particularly the Echo-Guided Life Support course (JF Lanctot and Max Valois), a Bedside Ultrasound Course for Nurses, an Acute Care Procedures Course and a Symposium for Ultrasound Educators on how to set up training programs. All in all, a lot of great stuff.

For more details and registration, please go to www.ccusinstitute.org.  And yes, of course there are CME credits by the University of Montreal.

As I said a few months ago – well, tweeted, to be exact – if you’re an acute care MD and NOT using bedside point-of-care ultrasound, you’re stuck in the 20th century… rude, but true.

Hope to see you there!

Philippe Rola

President, CCUS Institute

January 22, 2014

Blood transfusion and serum S1P levels in Sepsis: a leaky proposition? (Protecting the Glycocalyx Part1) #FOAMed, #FOAMcc

So in my ongoing quest to reframe my resuscitation step-by-step, I’ve been following up on a number of leads regarding the glycocalyx, as previously stated, and John’s reference to this article in a previous comment I feel is highly relevant. So this is it:

Synergistic Effect of Anemia and Red Blood Cells Transfusion on Inflammation and Lung Injury,  Anping Dong, Manjula Sunkara, Manikandan Panchatcharam, Abdel Salous, Samy Selim, Andrew J.Morris, and Susan S. Smyth

Advances in Hematology, Volume 2012, Article ID 924042, 8 pages

http://www.hindawi.com/journals/ah/2012/924042/

S1P (sphingosine-1-phosphate) is a regulator of endothelial permeability and immune function.  Uh-oh, why had I not heard of it? Hmmm…I don’t think it was in Guyton’s or in Harrison’s…and there hasn’t been an RCT about it… Ok, that about explains it.

So here are some factoids about S1P:

–       serum levels correlate with HCT as RBCs serve as an S1P reservoir.

–       anemic patients’ S1P levels are NOT fully replenished by transfusion, especially the older the transfused blood is.

–       In fact, older RBCs may actually remove plasma S1P.

The study:

They basically took mice, and in the first group, bled them (by 20ml/kg) and looked at inflammatory markers, lung permeability and also S1P levels. That’s basically the control group, and they noted that hemorrhage significantly increased inflammatory markers (interesting in and of itself) . They then transfused these mice using wither fresh, S1P-loaded RBCs, or 14-day old RBCs, and, lo and behold, the fresh blood resulted in less inflammation, increased S1P, but most importantly, markedly decreased lung permeability. So clearly, S1P attenuates transfusion associated lung permeability.

In the next group, they injected the mice with LPS following hemorrhage, and found a synergistic effect of blood loss and LPS on inflammation and lung permeability, as could be imagined. Following the LPS, they were transfused with one of four strategies: fresh blood, old blood, fresh blood + S1P or old blood + S1P.  Well, lung permeability still increased in all groups, but least in the fresh blood + S1P, and the old blood + S1P a close second.

Note, interestingly enough, that saline alone (the “control”) also increased lung permeability, highlighting yet again that NS (and probably any crystalloid) is not innocuous…

So here we’re looking at the finer effects of transfusion, and why, against “common-sense” correcting a patient’s hemoglobin level does not seem to help in all situations.  We have understood the aging issue and loss of deformability, but it is time to take a finer look.  We are familiar – at least in concept – with transfusion-associated lung injury or TRALI, but the mechanism remains unclear.

Summary and Take-Home message:

S1P infusions in sepsis?  Maybe someday…

Yes, this is an animal study, and the results cannot be extrapolated directly to humans, but it is food for thought, as John had mentioned.  Certainly at least this should tell us to keep and ear/eye out for human work with S1P, but personally, it will make me even more comfortable in not transfusing my septic patients with hb’s in the low 70’s and maybe even high 60’s (try repeating the cbc, more often than not comes back a couple points higher and you can avoid transfusion), and for those who are a little more aggressive with transfusion, maybe this should make them think twice…

I’ll add what I can dig up on human S1P studies soon.

cheers!

Philippe

January 14, 2014

Bedside Ultrasound Clip Quiz #7: What is it? #FOAMed, #FOAMcc

Ok, so no history for you. Say you’re doing a general bedside ultrasound exam on someone in shock and you see this:

What am I looking at?  (HINT we’re in the RUQ)

What should I be thinking of?

Answers tomorrow.  Lets see what you guys come up with!

Philippe

rubbadoc says:  What’s air doing there?

…and indeed he is right, it is air where there should not be. Now where is it exactly? (experts, refrain from answering…)

January 8, 2014

“But doctor, he’s vomiting blood!!!” – The NEJM GI Bleed article by Villanueva: Yup, time to reassess transfusion in GI bleed! @FOAMed, @FOAMcc

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Last january a highly anticipated paper came out in the NEJM (http://www.nejm.org/doi/pdf/10.1056/NEJMoa1211801), which should be a game changer, given a few provisos.  Villanueva et al reported on their large (almost 1,000 patients) randomized study on liberal (<90 mg/dl) vs restrictive (<70 mg/dl) strategy.  Interestingly but no longer surprisingly, the patients in the restrictive strategy did better.

Hmmm…sound familiar?  By now everyone  accepts the TRICC trial threshold of 70 in ICU patients, but when it first came out, there were a fair bit of disbelievers and concerned health care workers.  At the time, they excluded GI bleeds and acute coronary syndromes, understandably,

So what do the numbers say?  First lets see if there was any difference in the actual treatment. Definitely. In the restrictive group, 51% of patients required transfusion, vs 86% in the liberal group.  Sizeable difference. Now in terms of outcomes:

a. rebleeding decreased: 10% vs 16%

b. 6 week survival was better: 95% vs 91%

c. less adverse events: 40% vs 48%

But you know what, even if we throw out all the above, the absence of any difference would result in the same conclusion: there is no advantage to a higher hemoglobin goal in GI bleed.

…except for this important proviso: in their institution, UGI endoscopy was performed within the first 6 hours.  Now I’m not necessarily suggesting that the results would have been any different with a real-life, “random” timing of endoscopy, but in the spirit of scientific rigour, it is important to note.

Now there are a few important points to make that are highly relevant in the whole transfusion issue.

Why is transfusion bad? For those who may not be aware, here are a couple of reasons why transfusion looks good on paper but not necessarily so good for the patients: (a) due to stored red cell loss of deformability, the capillary bed can suffer micro-occlusion, and (b) there seems to be some immune suppression related to receiving transfusion. And I don’t (yet) have a clue what it might do to the glycocalyx…

So this is the sort of situation (not uncommon even in other clinical scenarios) where the physicians and nurses breathe a sigh of relief when seeing a nice number on a paper or a screen following transfusion, but the patient’s microcirculation is actually worse off than it was.

How valid is a hemoglobin value in GI bleed?  The answer to this is why we have MD’s after our names, and hopefully live up to that. Let me give you a quick anecdote: sometime in the past year I was called on to help a sick patient in the OR, a young woman with some post-partum bleeding who remained unstable. So the anaesthetists are concerned, the OB’s are trying to fix things, and she’s pretty unstable. A quick CUSE (critical ultrasound examination) shows she has a tiny IVC (almost virtual) and a hyperdynamic LV/RV with a near-100% EFs.  They were concerned because they had already given her fluid, etc…might she have suffered an amniotic embolism? So we were reassured that her RV was fine but clearly she needed more fluid of some sort (SBP 60’s, HR 140’s).  Just at that moment a call comes thru and the OB resident declares with a smile “its ok, her hemoglobin is 105!” and for a split second, there seems to be a sense of relief in the room, which worries me even more. I remind the resident that if he bleeds fast enough, the very last drop of his blood will have a very similar hemoglobin to the one he had while quietly sipping coffee at starbucks… So although we tend to use hemoglobin as an answer to “how much blood does my patient have,” what it really says is what the concentration of red cells is in the blood that my patient has – hence a clinical assessment (preferably with ultrasound) is required to at least determine in our minds whether our patient is empty or full, and only then can a hemoglobin value be properly interpreted. I doubt I would treat the same was someone with only 2 liters of blood going around with a hemoglobin of 75 versus someone with 4 liters of that same blood going around.  In that exact moment their hemoglobins are the same, but in all likelihood, in the ensuing hours, the first will continue to drop as the intravascular volume seeks to replete itself from the interstitial space and from possible GI intake or IV fluids.  So consideration has to be given to what fluids the patient has been or is receiving.  This is why we have MDs. If it was just about using a number, the clerk could manage our patient off the computer census and consult GI. Yep, its the N=1 concept again.

GI bleed = Trauma?   Conceptually, GI bleed is not that different from trauma.  You have a breach in vascular integrity. What are the determinants of rate of bleeding? The size of the hole and the pressure gradient.  Our body will try to shrink the hole with a fibrin mesh and a platelet plug and some vasoconstriction, and hypotension will decrease the pressure gradient.  That’s why in major trauma we don’t want to “stay and play” but want to “scoop and run” to an OR while just maintaining life until someone can plug the hole surgically (just look up some of Karim Brohi’s great #FOAMed lectures), because all that medical resuscitation (big crystalloid boluses) will do is blow those fibrin meshes away and increase the pressure gradient!  So aggressive fluid resuscitation may not be the best idea in GI bleed either. And yes, I’ve used tranexamic acid in bad GI bleeders while waiting for intervention.

Philosophical rambling… 

I think most of us forget that phrase…what was it again? Primum…primum non nocere?  Oh yes, we all said it, know it, but do we really remember to apply it to everything we do, every day? And why not? Because, in our desire to help, we more often than not feel like we have to “do something.”  And in truth, so does staff, families and the patients themselves.

Conclusion:

So, how will this change my practice?  It will make me completely comfortable in allowing my hemodynamically stable and nearly euvolemic (IVC can be seen and LV/RV not just a tachycardic blur) GI bleeder to have a hemoglobin of 70. Will I insist on an endoscopy within 6 hours? Not necessarily, but I will be monitoring (as I usually do) for any deterioration to get on the phone and push a little or a lot.

What’s next…?   I’m thinking down the line we might just see small volume resuscitation (100 cc at a timewith a glycocalyx-friendly albumin), a bolus and infusion of tranexamic acid and a quick endoscopic intervention will be the way to go, while keeping a hemoglobin no greater than 70…cuz who knows, maybe 60 or 50 might be better…

love to hear what anyone has to say!

Philippe

Check out Ken and I discussing this on the SGEMs Podcast:

SGEM#61: Blood on Blood (Transfusion Strategies for Upper GI Bleeds)

January 1, 2014

The N=1 concept. #FOAMed, #FOAMcc

First of all, happy holidays to all and happy new year!

Following a few requests, I’m gonna put up a few words about the N=1 concept, as I think it comes up in every single therapeutic and diagnostic strategy.

We do not treat a thousand, a hundred or even ten patients at a time.  As clinicians, we deal with a single patient, with a certain pathology, and his own, unique physiological pattern of response to that pathology.

In a medical utopia, we would be able to have a precise biophysiological profile of our patient – probably including parameters that either don’t yet exist, or are on the verge of being found or invented.  We would know, for instance, the degree of glycocalyx damage, the nature of this damage, the degree of subsequent capillary leak, the specific inflammatory cytokine pattern, and thus be able to use a potential combination of agonists and antagonists to favor healing, and tailor fluid therapy to the “just right” amount, avoiding both under-resuscitation and tissue edema. This would be similar to antibiotic sensitivity testing. Who, in this century so far, would deliberately not order sensitivities, instead satisfying themselves with a positive result and happy with empiric therapy?

Just in terms of biological variability, it is impossible to believe that all patients would respond best to a single goal or therapy. How can an MAP of 65 be as good for a septic hypertensive patient as it is for a young septic woman who normally walks around with an SBP of 110? Not that I don’t use that number myself most of the time, but certainly food for thought, and something to keep in mind when treating either of those “types” of patients…

And the answer to the N=1 riddle isn’t just subgroup analysis. The questions have to be answered in prospective fashion, built into the study design. Not easy work, and especially since we don’t yet even know what the key variables/questions are… But personally, as mentioned in an earlier post, I do now suspect that the ubiquitous glycocalyx holds some of those answers.

Let’s look at the whole fluid debate through the N=1 lens: it makes no sense whatsoever to debate crystalloids versus colloids. This negates thinking and only encourages near-religious fervour amidst both camps. Rather, look at your patient. Is he truly dehydrated/volume depleted or just volume responsive on the basis of vasodilation. If we want to restore the ICF and the interstitium, then crystalloids are probably better, but if we want to restore effective circulatory volume, then some measure of colloid may help avoid excessive edema, though even this can be debated. Even more important is the composition of the resuscitation fluid. Much as we adjust our TPN, we should probably design our resuscitation fluids, rather than only using Ringer’s Lactate (I say only just to drive the point that NS should not be used as a resuscitation fluid, unless repleting chloride is specifically necessary).

Now this may sound like a rant against large trials, but it isn’t. Absolutely invaluable information can be derived from these, it is just a matter of thinking how that information can benefit the one patient you have in front of you. And this isn’t easy. You have to put together your history, physical exam, bedside ultrasound exam and labwork. You can’t just say  “sepsis? 2 litres,” or any other such recipe (aka protocols).

ok, enough for a january 1st!

 

Love to hear what anyone thinks!

 

Philippe

 

December 18, 2013

Ultrasound MedED at CCUS 2014: for educators! #FOAMed, #FOAMcc

This year, as part of the pre-congress courses being held prior to the main symposium (may 10th and 11th), we are introducing a half-day symposium entitled: “The Educators‘ Symposium: How to integrate Bedside Ultrasound into Ungergraduate and Graduate Programs,” coordinated by Dr. Catherine Nix of the University of Toronto who has been the driving force behind U of T’s implementation of an ultrasound program for undergraduates.

Here is the preliminary programme, really good stuff for anyone involved in education, whether at the institutional level or even at the departmental level.

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program subject to (minor) changes…

Attendants may register for this independently or as part of the whole symposium. You can register at:

http://www.ccusinstitute.org/Symposium6.html

Stay tuned for more updates, and the final programme of the main conference should be out by next week.  Guess what, it’ll be a great place to meet @criticalcarenow, @bedsidesono, @EGLS_JFandMax, @nobleultrasound, and many more not yet deep into the #FOAMed or twitter-verse, but soon to be.

See you there!

Philippe